formFieldAppender

formFieldAppender is a Javascript module that allows you to add and remove an infinite number of similar form fields to a form.

Install

formFieldAppender is an ES6 module. Consequently, you'll need an ES6 transpiler (Babel is a nice one) as part of your Javascript workflow.

If you're already using NPM for your project, you can install formFieldAppender with the following command:

$ npm install @degjs/form-field-appender

Usage

Import formFieldAppender and create a new instance of it.

import formFieldAppender from '@degjs/form-field-appender';

let element = document.querySelector('div');

let instance = formFieldAppender(element);

By default, formFieldAppender will search the supplied element for an item that matches the itemClass parameter to use as its blueprint.

However, you can optionally provide either an HTML element or string representation of an HTML element as the item blueprint.

As an HTML element:

import formFieldAppender from '@degjs/form-field-appender';

let element = document.querySelector('div');
let itemBlueprint = document.createElement('div');

itemBlueprint.classList.add('phone-field__wrapper');
itemBlueprint.insertAdjacentHTML('afterbegin', `
    <label for="phone-field">Field</label>
    <input class="phone-field" name="phone-field" id="phone-field" type="tel">
`);

let instance = formFieldAppender(element, {
    blueprint: itemBlueprint
});

As a string representation of an HTML element:

import formFieldAppender from '@degjs/form-field-appender';

let element = document.querySelector('div');
let itemBlueprint = `
    <div class="phone-field__wrapper">
        <label for="phone-field">Field</label>
        <input class="phone-field" name="phone-field" id="phone-field" type="tel">
    </div>
`;

let instance = formFieldAppender(element, {
    blueprint: itemBlueprint
});

Parameters

blueprint

Type: HTMLElement or string
An HTML element or string representation of an HTML element that will be used as the blueprint for the repeating field.
Default: null

itemClass

Type: string
The class applied to each appended item.
Default: js-ffa-item

addTriggerSelector

Type: string
The selector for each item's add trigger.
Default: .js-ffa-add-trigger

removeTriggerSelector

Type: string
The selector for each item's remove trigger.
Default: .js-ffa-remove-trigger

idPatternAttr

Type: string
The attribute that contains the pattern that will be used to create each appended item's ID. A token of [[itemIndex]] in the pattern will be dynamically replaced by the item's current index, a token of [[itemElIndex]] will be replaced by the index of the element within the item, and a token of [[index]] will be replaced by a hyphenated combination of item and element index (i.e., ffa-id-3-2 for the third element inside the fourth item).
Default: data-ffa-id-pattern

namePatternAttr

Type: string
The attribute that contains the pattern that will be used to create each appended item's name attribute. See idPatternAttr description for available token values. Default: data-ffa-name-pattern

forPatternAttr

Type: string
The attribute that contains the pattern that will be used to create each appended item's for attribute. See idPatternAttr description for available token values.
Default: data-ffa-for-pattern

disabledClass

Type: string
The class applied to an item when it's hidden/disabled. This class can be used to visibly hide disabled items with CSS.
Default: is-disabled

initialReindex

Type: number
The first index value applied to added items.
Default: 1

firstItemIsRemovable

Type: boolean
Determines whether the first item can be removed.
Default: true

onlyLastItemIsRemovable

Type: boolean
Determines whether a "remove" trigger is added to all items, or only the last item.
Default: false

onItemAddCallback

Type: function or null
An optional callback that's fired whenever an item is added.
Default: null

onItemRemoveCallback

Type: function or null
An optional callback that's fired whenever an item is removed.
Default: null

resetNewItemFormVals

Type: boolean
Determines whether the fields in added items contain the values of the original item/template.
Default: true

Methods

.destroy()

Parameters: none
Destroys the formFieldAppender instance.

.getItems()

Parameters: none
Returns an array of the items currently added to the formFieldAppender instance.

Browser Support

formFieldAppender depends on the following browser APIs:

• Object.assign: Documentation | Polyfill
• Array.from: Documentation | Polyfill
• Element.closest: Documentation | Polyfill

To support legacy browsers, you'll need to include polyfills for the above APIs.